Writing element construction



Dec. 3, 1968 c. L. MALM WRITING ELEMENT CONSTRUCTION Filed Oct. 17 1966 vl/E/vroe. Caer/s L. MnL/w United States Patent O 3,414,359 WRITING ELEMENT CONSTRUCTION Curtis L. Malin, Norwalk, Conn., assignor to Paper Mate Manufacturing Company, Santa Monica, Calif., a corporation of Delaware Filed Get. 17, 1966, Ser. No. 587,173 12 Claims. (Cl. 401-109) ABSTRACT F THE DISCLOSURE A simple writing assembly with a concealed retractproject mechanism wherein a rear barrel section is provided with a hollow rear portion mounted for rotation: a hollow translating plunger has a rear end portion slidable into the rotatable rear portion and a front portion provided with external feed threads adapted to engage internal feed threads fromed adjacent the front end of the rear barrel section. The plunger is retained for limited axial movement by a hollow junction having external threads in fixed engagement with some of the internal feed threads of the rear barrel section and other threads for engagement with internal connecting threads on a front barrel section.

Although this invention is applicable to its utilization in various types of writing instruments, including nib pens, it is particularly adapted for use in ball point pens which heretofore have usually incorporated longitudinally or laterally depressible Ibuttons at their rearward portions for actuating .a project-retract mechanism. Such mechanisms have disadvantages in that they take up considerable space in the pin and utilize a number of small, relatively complicated parts which increase manufacturing and assembly costs. Such mechanisms are often susceptible to being damaged and to malfunctioning by reason of repeated use. Moreover, in many such instruments, the tip of the cartridge moves into an over-extended iposition during its movement from a retracted to a projected writing position and such over-extended movement is deemed undesirable. In many prior constructions, this projectretract movement is accompanied by a clicking noise and such clicking may be annoying to the user.

The present invention embodies a construction wherein the union `between the two portions of a barrel is attained by the use of a hollow junction which not only provides a means for attaching the two barrel sections together, but also provides means for retaining a project-retract mechanism within the upper portion of the barrel.

The present invention is directed to a simple and effective construction wherein the tip of the cartridge is caused to project into writing position by a simple rotation of the rear portion of the barrel and allowed to move into retracted position by a reverse rotation of such rear portion. The retraction is preferably assisted by a retracted spring. One of the major advantages is that standard or conventional cartridges (having either small diameter ink reservoirs or large diameter reservoirs) normally used in most of the present produced ball point pens can be also used in the pen of this invention. This obviates the necessity of making, storing and supplying cartridges of a special configuration, size or style for pen bodies made pursuant to this invention. Cartridges can be replaced with ease. None of the working parts are exposed to tampering and are suficiently sturdy and foolproof to last indefinitely. The manufacture and assembly of the pen is simple. Moreover, the pen is slim since the maximum wall thickness of the barrel (at the zone where the barrel sections are removably connected for replacing cartridges) is only the thickness needed to provide a threaded connection between the barrel sections; this permits the utilization of large diameter (so-called jumbo) cartridges.

3,414,359 Patented Dec. 3, 1968 ICC The construction and assembly herein disclosed has utility in all writing instruments, in addition to those specifically illustrated hereafter, which employ a twosection barrel, selectively separable to permit replacement of a cartridge, whenever the upper or rear section barrel is to contain an element or subassembly which need be inserted through the open or forward end of the rear barrel section during assembly or manufacture and be retained therein even when the barrel sections are subsequently separated. The construction herein disclosed permits most effective utilization of space within the barrel and gives rise to a slim, smooth instrument which is easily assembled.

It is an object of the present invention therefore to disclose and provide a simplified construction for retractable writing instruments.

An object of the invention is also to provide a construcstruction which permits the use of relatively large standard `sized cartridges in a slim, short rpen.

A further object of the invention is to disclose and provide a writing instrument employing a forward barrel section and a rear barrel section, the two barrel sections being joined by a hollow junction which irremovably retains a project-retract element insertable through the open end of the rear barrel section and simultaneously provides means for selectively connecting the rear barrel section to the mating end of the forward barrel section in actual alignment.

A still further object is to provide a writing instrument assembly including a hollow, forward barrel section, a hollow rear barrel section having a rear end portion mounted for selective rotation coaxially with such barrel section and being restrained from movement along such axis, and a translating subassembly insertable into the rear barrel section through the open end, whereby rotation of the rear end portion provides means for either projecting or retracting a cartridge within the assembly.

These and various other advantages and objects of the present invention will become apparent from those skilled in the art from the following detailed description of an exemplary form of the invention, reference being had to the appended drawings in which:

FIG. 1 is a longitudinal view mostly in section of a retractable ball point `pen employing the present invention;

FIG. 2 is an enlarged longitudinal sectional view of the retract-project mechanism portion of the pen shown in FIG. 1 with the cartridge in its projecting writing position;

FIG. 3 is a longitudinal sectional view of the rear portion of the pen with the cartridge in its retracted position;

FIGS. 4 and 5 are transverse sectional views taken along the planes IV-IV and V-V in FIG. 2.

The exemplary form of writing instrument illustrated in the drawings com-prises an external barrel composed of a hollow forward barrel section 1 having a rearwardly opening mating end 11 formed -with internal threads 12 adjacent such end; and a hollow rear barrel section 2 having a rear end portion 3 mounted thereon for selective rotation coaxially with such barrel section 2, such rear barrel section having a forwardly opening open end 21 provided with internal threads 22 adjacent such open end. The barrel sections 1 and 2 are preferably cylindrical in cross-section and perferably tapered toward their opposing ends. The rear end portion 3 is preferably hollow and generally frusto-conical in external form; it is mounted or connected to the rear barrel section 2 in a suitable manner for manual selective rotation about the axis of the rear barrel section; lthe rear -portion 3 may be of one piece or of several pieces interengaging each other so as to permit the use of differently colored pieces for decorative effect. In the examplary form illustrated, the external 3 rotatable portion may comprise coaxial intertngaging elements 3'1, 32 and end cap 33. The element 31 may be provided with oppositely extending bearing bushing extensions of smaller diameter rotatably engaging the internal surfaces of the rear barrel section 2 and the element 32 in order to facilitate alignment and relative rotatability.

The exterior rotatable elements 31, 32, 33 may tbe rotatably mounted upon the rear end of the rear barrel section 2 in any suitable manner; in order to increase the resistance to bending and interconnect these elements, the rotatable portion may include a thin metal preformed liner 34 whose upper end may grasp an inwardly extending boss carried -by the end cap 33 with a press it, and whose forward portion is cylindrical in form with a slip tit against element 31 and whose forward end is provided with an outwardly extending ange 35 rotatably engaging an inwardly extending shoulder of the rear Ibarrel section 2 as clearly shown in FIGS. 2 and 3. The internal lsurface of element 32 and liner 34 is preferably provided with at least two ilat internal surfaces in planes parallel to the axis of the device whereby manual rotation may be transmitted from the element 32 to a plunger 40. Conveniently, the internal surface of 32 is made polygonal (pentagonal or hexagonal in cross-section) as shown in FIG. 4, and that portion of metal 'liner 34 which extends through element 32 is of similar polygonal cross-section so as to transmit rotation of the rear end portion 3 through the liner 34 to the end 41 of a plunger 40 (subsequently described). The liner 34 is inserted through the forwardly opening open end 21 of the rear |barrel section into holding engagement with the cap 33, thereby holding the entire rear outer hollow portion 3 in rotatable engagement with the rear barrel section 2.

The hollow translating plunger 40 is also inserted into the rear barrel section 2 through the forwardly opening open end 21, this plunger 40 Ibeing provided with a rear portion 41 having a polygonal exterior configuration permitting it to be slidably received within the rear portion of the liner 34. The for-ward portion of the translating plunger 40 is preferably cylindrical, the outer surface of the forward portion of this plunger lbeing provided with power transmitting threads 43 adapted to engage the threads 22 formed on the inner surface of the rear barrel section 2. These threads are preferably of the buttress, square or acme type and of relatively coarse pitch. A rearwardly facing stop shoulder 44 occurs at the transition between the forward hollow portion 42 and the rear portion 41 of the plunger, this shoulder being adapted to cooperate with the flange 35 (as best seen in FIG. 3) to stop the rearward progress of the plunger within the rear barrel section. The length of the plunger 40 is shorter than the length of the rear barrel section 2.

Means are also provided for irremovably retaining the plunger 40 within the rear barrel section and simultaneously providing means for selectively connecting the rear barrel section to the mating end of the forward barrel section 1 in axial alignment. Such means comprise a junction element generally indicatde at 5. The rear portion of the hollow junction is provided with upstanding external threads 52 adapted to cooperatively engage the threads 22 formed on the interior Isurface of the rear barrel section 2 adjacent the forwardly opening end 21; the forward end of the junction 5 is provided with threads 51 capable of being cooperatively engaged with the threads formed on the inner surface of the rearwardly opening mating end 11 of the forward barrel section 1. After the rotatable rear end lportion 3 and its liner 34 has been placed on the rear portion of the barrel section 2 and the plunger bas been inserted, the junction 5 is screwed into the forwardly opening open end 21 and cemented in place. The junction 5 may carry an outstanding annular stop flange 53: which limits the extent to which it may be screwed into the rear barrel section 2, leaving only the externally threaded forwardly extending portion 51 available for use as a connecting means to which the Cil forward barrel section 1 may be attached. In actual practice, a decorative Iband or ring provided with a inwardly extending flange may be held in position by cooperation of the stop flange 53 and the end 21 of the rear barrel section 2.

With the rear barrel section assembled as described hereinbefore, it is now only necessary to insert a cartridge, containing an ink reservoir 6, a writing tip 7 and a breather cap 8 into the hollow forward barrel section 1, a retracting spring 9 being generally employed between the forward end of the interior of the barrel and such cartridge. The forward barrel section can now be connected to the upper or rear barrel section by engaging the internal threads 51 on the junction with the internal threads 12 on the forwand barrel section 1. The breather cap 8 extends into the plunger and is urged thereagainst by the retraction spring 9. The pitch of threads 52 is generally selected so that one complete revolution of the external or rotatable rear end portion 3 will cause the plunger 40 to advance longitudinally and thereby cause the tip 7 of the cartridge to project into writing position; a reverse rotation of portion 3 will permit the tip to be Withdrawn into retracted position. Rearward motion of the plunger (and its contained cartridge) is limited by cooperation of the shoulder 44 with the ange 35; forward or projected position of the plunger and cartridge is limited by cooperation or contact of the end 45 of the plunger with the end of the junction element 5.

The feed threads or power transmitting threads 52 are generally of Igreater pitch than the connecting threads 51. It is to be noted that the mating or opposing ends of the front and rear barrel sections are of substantially the same external diameter thereby insuring the production of a writing instrument having confluent surface contours. The thickness of the walls at said junction do not exceed the thickness of the barrel and the junction element. As a result, a relatively slim barrel can easily accommodate a cartridge having a large diameter reservoir section, insuring a writing instrument of protracted life.

It is to be understood that the junction construction here disclosed may be used in various writing instruments having different types of retract-project mechanisms, or none at all. The translating plunger preferably converts the rotation of the rear end portion into an axial movement which projects and retracts the writing unit: the internal feed threads of the rear barrel section perform a dual purpose in that they cooperate with the plunger and also engage and hold the junction element in position. The end of the plunger and the opposing end of the junction also cooperate to positively limit the extent to which the writing tip projects when in writing position. Although a cartridge provided with a ball-type point is illustrated, a stylographic or porous tip can be used.

All changes coming within the scope of the claims are embraced thereby.

I claim:

1. In a writing instrument assembly:

a hollow forward barrel section having a writing tip aperture at one end and a rearwardly opening mating end provided with internal connecting threads adjacent said matin-g end;

a hollow rear barrel section having a rear end portion mounted for selective rotation coaxially with respect to such rear barrel section and restrained from movement along such axis, said rear |barrel section having a forwardly directed open end and internal feed threads adjacent said' open end;

a hollow translating plunger insertable into said rear barrel section through said open end, said plunger carrying external feed threads for cooperation with the internal feed thread-s;

a hollow junction for irremovably retaining the plunger within the rear barrel section and providing means Ifor selectively connecting the rear barrel section to the mating end of the forward -barrel section in axial alignment;

one end of said junction being provided with external feed threads in lfixed engagement with the feed threads of the rear barrel section and the other end being provided with external connecting threads for selective connection to the mating end of the forward barrel section.

2. A writing instrument assembly as stated in claim 1 wherein the plunger is provided with a rearwardly facing stop shoulder for cooperation with the rear lbarrel to limit rearward movement of the plunger, the forward end of said plunger being adapted to abut the junction to limit forward motion of the plunger.

3. A writing instrument assembly as stated in claim 1 wherein the hollow translating plunger is provided with rearwardly disposed means in axially slidable, rotationtransmitting relation to said selectively rotatable rear end portion of the rear 'barrel section.

4. A writin-g instrument assembly as stated in claim 1 wherein the hollow translating plunger is provided with rearwardly disposed means in axially slidable, rotationtransmitting relation to said selectively rotatable rear end portion of the rear barrel section; and

wherein the feed threads are of greater pitch than the connecting threads.

5. A writing instrument assembly as stated in claim 1 wherein the hollow translating plunger is provided with rearwardly disposed means in axially slidable, rotationtransmitting relation to said selectively rotatable rear end portion of t-he rear barrel section;

wherein the plunger is provided with a rearwardly facing stop shoulder for cooperation with the rear Ibarrel to limit rearward movement of the plunger, the forward end of said plunger being adapted to abut the junction to limit forward motion of the plunger; and

wherein the feed threads are of greater pitch than the connecting threads.

6. A writing instrument assembly as stated in claim 1 wherein the hollow translating plunger lis provided with rearwardly disposed means in axially slidable, rotationtransmitting relation to said selectively rotatable rear end portion of the rear barrel section;

a writing cartridge removably positioned within the assembled barrel sections, said cartridge having a writing tip projectable through said writing tip aperture, an ink reservoir and a rear portion extending into the translating plunger; and

a biasing spring urging the cartridge into retracted position.

7. A writing instrument assembly as stated in claim 1 wherein the hollow translating plunger is provided with rearwardly disposed means in axially slidable, rotation-transmitting relation to said selectively rotatable rear end portion of the rear barrel section;

wherein the plunger is provided with a rearwardly facing stop shoulder for cooperation with the rear barrel to limit rearward movement of the plunger, the forward end of said plunger being adapted to abut the junction to limit forward motion of the plunger; and

a writing cartridge removably positioned within the assemblied barrel sections, said cartridge having a writing tip projectable through said writing tip aperture, an ink reservoir and a rear portion extending into the translating plunger;

and a biasing spring urging the cartridge into retracted position.

8. A writing instrument assembly as stated in claim 1 wherein the feed threads are of greater pitch than the connecting threads.

9. A writing instrument construction comprising: a hollow forward barrel section having a writing tip aperture at one end and a rearwardly opening mating end provided with internal connecting threads adjacent said mating end;

a hollow, rear barrel section having a forwardly directed open end and internal feed threads adjacent said open end, the external diameter of said rear barrel section adjacent its open end being virtually equal to the external diameter of the mating end of the forward barrel section whereas the rear end portion of the rear barrel section is of progressively smaller external diameter;

a project-retract element insertable through said open end of the rear barrel section;

a hollow junction for irremovably retaining the element within the rear barrel section and providing means for selectively connecting the rear barrel section to the mating end of the forward barrel section in axial alignment;

one end of said junction being provided with external feed threads in fixed engagement with the feed threads of the rear barrel section and the other end `being provided with external connecting threads for selective connection to the mating end of the forward barrel section.

10. A writing instrument construction :as stated in claim 9 wherein said junction includes a circumferential shoulder to position and limit the engagement of the junction with respect to said rear barrel section.

11. A writing instrument assembly as stated in claim 1 wherein the rotatable rear end portion is hollow and a part thereof is of polygonal internal section;

and the translating plunger is provided with a rear portion of polygonal section slidably insertable into the rotatable hollow rear end portion of the rear barrel section.

.12. A writing instrument assembly as stated in claim 1 wherein the rotatable rear end portion of the rear barrel section is hollow and includes a stlfening liner connecting said rotatable portion to the rear barrel section, a portion of said liner having a polygonal internal cross-section;

and the translating plunger is provided with a rear portion of polygonal cross-section slidably insertable into said liner for limited axial movement, said external feed threads being carried on the front portion of the plunger and movably engaging the internal feed threads of the rear barrel section.

References Cited UNITED STATES PATENTS 1,386,817 8/1921 Wade 401-116 2,454,086 ll/ 1948 Randolph 401-116 3,272,184 9/1966 Crowley 401--116 3,292,592 12/1966 Chapman et al. 401--116 FOREIGN PATENTS 141,271 4/ 1920 Great Britain. 254,654 12/1912 Germany.

LAWRENCE CHARLES, Primary Examiner. 

